Hoses used for filling and emptying gasoline tank trucks have end fittings thereon that permit the hose to be connected in a fluid tight manner to a valved fitting on the tank truck. In some arrangements the two fittings are sealed relative to each other by an elastomeric flat gasket that engages opposed faces on the fittings and simply squeezed thereby for sealing the joint when the fittings are attached to each other by cam action of a quick connect and disconnect mechanism. Such joints are not altogether satisfactory because with tolerance variations the travel of the fittings toward each other by cam action may vary so much that in some assemblies there will be insufficient pressure exerted on the gasket to establish a seal and in other assemblies the compression will be so great that it is difficult to operate the cams to their full lock position. In the latter case there will also be excessive wear on the surfaces contacted by the cams.